Calibre is free and open source e-book software for Windows, Mac and Linux that can be used to download, store, organize, edit, and convert e-books.
Manage your e-book collection
Intuitive and user-friendly interface, advanced search and sorting functions, and many more useful features. Calibre not only can download all the metadata for an e-book (things like title, author, publisher, ISBN, tags, cover or summary) but will also allow you to edit or create metadata in existing or new fields.

Comprehensive e-book viewer
calibre has a built-in e-book viewer that can display all the major e-book formats. It has full support for Table of Contents, highlighting, bookmarks, CSS, read aloud, a reference mode, printing, searching, copying, multi-page view, embedded fonts, and on and on.
Edit, convert books
calibre can convert dozens of file types. When converting, you can also automatically change the book’s style, create a table of contents or improve punctuation and margins. calibre will also detect the format that’s best suited for your device on its own.
The built-in editor allows you to edit e-books in the most popular e-book formats, EPUB and Kindle. The editor has many sophisticated features to make editing the innards of e-books as easy and efficient as possible.
Download news/magazines from the web
calibre can make sure you know what’s happening and automatically deliver stories to your device from hundreds of news sources like The Economist, New York Times, New Yorker Magazine, The Guardian, BBC News, National Geographic, CNN, The Wall Street Journal, The Washington Post, The Atlantic, Scientific American, Wired Magazine, The Telegraph, Forbes, Ars Technica…
You can also teach calibre to deliver news from completely different sites or take advantage of any RSS feed. No searching, no waiting, no hassle.
Get books online
Calibre helps you find the e-books you want by searching the websites of various commercial and public domain book sources, such as Amazon, Archive.org, Baen Ebooks, Barnes and Noble, Bean Ebooks DE, Bubok Portugal, Bubok Spain, ebook.de, ebook.nl, Ebookpoint, eBooks.com, Ebooksgratuits.com, Empik, Feedbooks, Google Books, Kobo, Legimi, LitRes, ManyBooks, Mills and Boon UK, MobileRead, Nexto, Pragmatic bookshelf, Project Gutenberg, Publio, RW2010, Smashwords, Virtualo, Weightless Books, Woblink, Wolne Lektury, etc.
Share, transfer, backup your library easily
Convert and send the best file format to any e-reader or devices.
calibre comes with a handy web server to host your library so you can safely share all (or just some) of your e-books with anyone you choose or access them yourself from anywhere, using any device you like.
calibre has also some useful backup and import/export features.
Download Calibre
Get this free ebook program from its website here.